表格视图单元格中的情节提要板图像视图

Question

I have an imageview inside a tableview cell of tableview. what i want to achieve is it should resize the imageview according to the image it contain dynamically.Currently I have it like this:

Answer 1

I had this same exact issue not long ago.

First, you should set image content mode to Aspect Fit, BUT it is not enough.

You will have to change imageView's aspect ratio constraint every time you want to load a new image. Basically, what you need to do is:

1. Get your image's width and height
2. Calculate aspect ratio let aspectRatio = Float(image.height) / Float(image.width)
3. Use that aspect ratio to create a new aspect ratio constraint for your image view.

This is a copy-paste (with added comments) of my code where I managed this issue. Hope it will help you.

    // aspectRatioCnst is IBOutlet reference to aspect ratio constraint I've set on mainImageView in Storyboard
    if let aspectRatioCnst = aspectRatioCnst {
        aspectRatioCnst.isActive = false
    }
    let aspectRatio = Float(imagePost.height) / Float(imagePost.width)
    aspectRatioCnst = NSLayoutConstraint(
        item: self.mainImageView,
        attribute: NSLayoutAttribute.height,
        relatedBy: NSLayoutRelation.equal,
        toItem: self.mainImageView,
        attribute: NSLayoutAttribute.width,
        multiplier: CGFloat(aspectRatio),
        constant: 0)
    if let aspectRatioCnst = aspectRatioCnst {
        self.mainImageView.addConstraint(aspectRatioCnst)
        aspectRatioCnst.isActive = true
        self.mainImageView.layoutIfNeeded()
    }
    if let image = imagePost.loadedImage {
        self.mainImageView.image = image

    } else if let imageURL = URL(string: imagePost.fileURL) {
        DispatchQueue.global(qos: .background).async {
            // UIImage extension with downloadedFromURL method
            UIImage.downloadedFromURL(url: imageURL, withCallback: { (image) -> (Void) in
                DispatchQueue.main.async {
                    self.imageLoadingActivityIndicator.stopAnimating()
                    self.mainImageView.image = image
                    self.imagePost?.loadedImage = image
                }
            })
        }
    }

Answer 2

First set your bottom content a height like this,

Then set your image constrains like this,

Then do this in your code,

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {

        let imageNew  = UIImage(named: "test") //Set your image here
        let oldWidth = imageNew!.size.width
        let scaleFactor = tableView.frame.size.width / oldWidth

        let newHeight = imageNew!.size.height * scaleFactor
        let newWidth = oldWidth * scaleFactor

        //Finally to get cell size just add the bottom part height for othercontents to ImageHeight here
        let CellSize = CGSize(width: newWidth, height: (newHeight + 40))
        return CellSize.height

    }


     func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! TableViewCell
        cell.NewImage.image = UIImage(named: "test")
        return cell

    }

You should get somthing like this,